Light source



Sept. 21, 1948. J. 1.} COX 2,449,880

LIGHT SOURCE Filed May 16, 1945 /Z INVENTQR JAMES L. C OX NEYS PatentedSept. 21, 1948 LIGHT SOURCE James L. Cox, Ramsey, N. J., assignor toDuro- Test Corporation, North Bergen, N. 1., a corporation of New YorkApplication May 16, 1945, Serial No. 594,033 1 Claim. (01.. 176-122)This invention relates to a novel form of light source.

One object of this invention is to provide a new form of light sourcewhich becomes luminescent upon agitation.

Another object of the invention is to provide a light source which maybe energized without the use of any form of usual power supply.

A still further object of the invention is to provide a light source inthe form of a transparent evacuated vessel having enclosed therein asmall quantity of a rare gas or a mixture of several rare gases, mercuryand a phosphor, preferably in finely divided or powdered form,

Other and more detailed objects of the invention will be apparent fromthe following disclosure of one embodiment thereof such as thatillustrated in the attached drawings.

This invention resides substantially in the combination, construction,arrangement and relative location of parts, all as will be described indetail below.

In the accompanying drawings- Figure 1 is a side elevational view of alight source in accordance with this invention with a portion brokenaway to show the interior thereof;

Figure 2 is a cross-sectional view taken on the line 2-2 of Figure l;and

Figure 3 is a fragmentary view similar to that of Figure 1 showing amodified structure.

All the well known forms of practical light source of the electricaltype are energized to the point of luminescence by the application ofelectrical potentials thereto so as to pass current either through thewire or a gaseous atmosphere. There are some other forms of lightsources not yet at a practical stage which are capable of pro ducinglight after exposure to other light sources such as the sun orartificial light. There are still other known but impractical forms oflight sources by mean of which light is produced mechanically. The lightsource of this invention diifers in major respects from all these knownsources of light.

In accordance with this invention a vessel IU of any suitablecon-figuration and made of transparent material such as glass, andpreferably Pyrex glass is evacuated to the degree commonly employed inproducing incandescent and fluorescent lamps and sealed off. Theinterior wall of the vessel is coated with a suitable fluorescentmaterial or mixtures thereof, as for example zinc silicate and beforesealing off a small quantity of rare gas such as neon, argon and thelike is introduced therein as well as a small globule of mercury. Theluminescent coating has been diagrammatically illustrated by thereference numeral II and the mercury globule by the reference numeral12.

This self-contained unit becomes alight source upon agitation as byshaking. Such agitation causes the fluorescent coating to becomeluminescent.

The modified construction of Figure 3 is a preierred embodiment of thedevice. In this form the difference, as illustrated over that of thepreviously described form, is that the fluorescent powder instead ofbeing applied to the interior wall of the vessel I0 is placed therein inthe form of a small body of loose powder as illustrated at ll. Asbefore, of course, the vessel I0 is evacu ated to the appropriate degreeand a rare gas content is included. Thus to crystallize the differencebetween the structures of Figures 1 and 2 and Figure 3, the fluorescentmaterial is in the form of a coating in the former and a loose quantityof powder in the latter. In the modified arrangement when the vessel isagitated the droplet of mercury 12 and the fluorescent powder ll engagein violent frictional contact with each other, the gas content of thevessel and the interior wall thereof, resulting in the generation ofvisible light.

It is not clearly understood why this device so operates, but it isbelieved that the agitation causes the development of a static chargewhich ionizes the gaseous content of the vessel. Thereupon thefluorescent coating becomes visibly luminous either by ionic bombardmentor by the impingement thereon of ultra-violet rays produced by suchagitation. It is possible the" there is some other more correctexplanation of the electronic or other forces which cause luminescence,and therefore the above possible explanation of the operation is givenpurely as speculation.

As those skilled in the art will appreciate, there is a wide range ofsuitable coating materials for the interior of the vessel having otherknown characteristic efficiency of fluorescence and color. Likewise, itis known that mixtures of these various materials may be used for thesame purpose. Other suitable coating materials which can be specificallynamed are zinc beryllium silicate, calcium tungstate and the like. It islikewise well known that various rare gases may be used and that they incombination with the different coating materials will affect the colorcharacteristics of the source. It is also well understood that theamount and pressure of the gas within the vessel can be varied with wellknown changes in the characteristics of these devices. It is understoodthat advantage may be taken of all of this knowledge in adapting thelight source of this invention to various purposes and uses. It willalso be understood that the quantity of mercury used is not critical andthat the device will produce light without the use of the fluorescentcoating.

Since undoubtedly the basic cause of luminescence is a result of thefrictional eifect of the mercury on the gas and/or coating the shape ofthe glass vessel may be modified to increase this frictional eil'ect.Thus in the form of structure illustrated in the attached drawing thevessel is provided with an elongated restricted central portionterminating in bulbous ends for the purpose of increasing suchfrictional effects. It therefore follows that various other physicalforms of the vessel which would contribute to this frictional effect arewithin the scope of this invention. For example other forms ofconstructions as well as baiiles could be used to intensify thefrictional effect.

Upon consideration it will be seen that a light source of this kind mayhave many uses of which the following are merely suggestive. It could beused as a signaling device especially in emergency conditions; it couldbe used as an indicator lamp, for example an automobile tail lamp.These, latter uses are indicative of the fact that it could be used inany place where it would be subject to constant agitation and thereforeremain constantly luminous. It could be used for novel effects such asfor example in stage productions and other similar spectacles. Finally,a very practical use would be to employ it as a fish lure, where byproper agitation of the lure it would contribute greatly to the fabledrealm of Ash p87- chology. The above are indicative of the possibilitiesof use of a device of this kind.

In view of the fact that the subject matter of the invention is capableof considerable variation within the skill and knowledge of the art towhich it is related, I do not desire to be strictly limited to thedisclosure as given for purposes of illustration, but rather to thescope of the appended claim.

What is claimed is: g

A method of generating visible light comprising mechanically agitatingliquid mercury in contact with loose phosphor particles in an atmosphereof rare gas at low pressure.

JAMES L. COX.

REFERENCES CITED The following references are of record in the iile ofthis patent:

' UNITED STATES PATENTS Number Name Date Re. 21,150 Von Lepel July 25,1933 966,204 Hewitt Aug. 2, 1910 1,698,691 Buttolph Jan. 8, 19292,030,439 Fritze Feb. 11, 1938 2,117,544 Coustal May 1'7, 1938 2,118,452LeBel May 24, 1938 2,182,732 Meyer Dec. 5, 1939 2,184,530 Penney Dec.26, 1939 2,225,495 Germer Dec. 17, 1940 2,355,117 Smith Aug. 8, 1944FOREIGN PATENTS Number Country Date 605,242 France Feb. 13, 1926

